1. Field of the Invention
This invention relates generally to a device for use with a programmable hearing instrument and, more particularly, to an interface module that can be easily connected between the hearing instrument and the programming system that adjusted the response of the hearing instrument.
2. Description of the Background
Auditory prosthesis, also known as hearing instruments or hearing aids, have been well-known for a long time. Recently, because of advances in semiconductor technology, such auditory prosthesis have become quite compact and have been able to include numerous features that were previously prohibited due to size and power constraints. For example, since around 1984 hearing instruments have incorporated means for modifying the response of the hearing aid. That is, it is possible for a hearing technician to tailor the response curve of the hearing instrument to the specific hearing impairment of the user for whom the instrument is being fitted. This is typically accomplished by storing the appropriate response coefficients in a memory circuit located inside the actual hearing instrument. The coefficient values are externally controllable by the hearing technician using a programming system and such a hearing instrument is generally referred to as a digitally programmable hearing aid.
While this kind of programmable hearing aid provides advantages to the user, there are also a number of problems associated with delivering the signal from the programming system to the hearing aid. Such problems are particularly present if the hearing aid is of the type known as an in-the-ear hearing aid. This type of hearing aid is quite small in size and has a reduced volume so as to fit, as the name implies, completely in the ear of the user. Other hearing aids known as behind-the-ear hearing aids have also been made much smaller in recent times due to the advances in semiconductor technology and manufacturing techniques.
In the case of the in-the-ear hearing aid, it is necessary to eliminate any signal input devices, in the form of input/output ports, that take up space on the hearing aid in order to achieve a cosmetically appealing instrument and one that is small enough to reside in the user's ear.
One approach to eliminating the necessary input/output ports or electrical connectors is to perform the digital programming by wireless transmission using ultrasonic signals or radio frequency transmissions. Both of these approaches, while eliminating the need for the input/output ports, require the use of additional circuitry inside the hearing aid in order to filter and demodulate the transmitted signals.
Another approach that has been proposed to accomplish connection of the programming signal to the hearing aid is to use a so-called battery pill. This approach involves removing the battery from the hearing aid and substituting a specialized connection device that approximates the exact configuration of the battery, but which has an electrical cable connected to it that is connected back to the programming system. The battery pill typically has three electrical contact areas on its outer surface, two of which provide the power to the hearing aid, such as might be normally provided by the battery, and the third contact is connected to another contact electrode inside the hearing aid. That third contact electrode is used for sending and receiving signals between the programming system and the hearing aid. One system of this kind is shown and described in U.S. Pat. No. 4,961,230.
All of the systems described above that have been known heretofore require either the use of additional circuitry to detect and decode the programming signals or have specialized mechanical requirements, such as having a battery door that permits the insertion of the battery pill, for example. In addition, none of the above systems permit interfacing with additional peripheral equipment without redesigning the hearing aid interconnection system.